How do guide dogs know where to go?

A guide dog is taught a variety of behaviors and signals that the user will then "command" the dog to respond. The dog is also taught intelligent disobedience, such as to disobey a given command that if obeyed would result in harm or death to a user.
The human handler tells the dog where to go. The dog may also learn through repetition paths that are frequently taken by name, such as "home" or "office."